Human papillomavirus (HPV) infection is a major risk factor for cervical cancer, demanding improved diagnostic strategies to distinguish between transient infections and those requiring intervention. Background: This systematic review and meta-analysis evaluated the diagnostic accuracy of HPV L1 immunocytochemistry (ICC) in detecting high-grade cervical intraepithelial neoplasia (CIN2+). Methods: We systematically analyzed data from 15 studies (PROSPERO 2022 CRD42022375916) comprising 3804 cervical smears with varying cytological findings (NILM to ≥ASC-US). Results: The pooled sensitivity for detecting CIN2+ was 80.7% (95% CI: 76.2–84.4%); however, substantial heterogeneity was present (I² = 65.97%, p < 0.001). Similarly, the pooled specificity was 56.9% (95% CI: 49.6–64%), with even higher heterogeneity (I² = 90.46%, p < 0.001). This considerable heterogeneity, which may be attributable to methodological variations or regional differences in HPV prevalence and genotyping, limits the generalizability of these findings. Furthermore, the moderate specificity suggests a high rate of false positives, limiting the clinical utility of HPV L1 ICC as a standalone diagnostic test. Conclusions: In conclusion, although HPV L1 ICC exhibits acceptable sensitivity for detecting CIN2+, its limitations, including low specificity and substantial heterogeneity, necessitate its use as an adjunct to other established diagnostic methods, alongside further research to enhance its diagnostic performance, and necessitate its use as a supplementary test alongside established diagnostic methods, pending further research to refine its clinical utility.

Background/Objectives: Atypical cytological findings in cervical screening, such as ASC-US, ASC-H, and AGC, present a clinical challenge due to their variable risk of underlying high-grade lesions. The precise stratification of this risk is crucial for effective patient management. This study aimed to correlate Bethesda cytology categories with HPV genotyping, including viral load, and histological follow-up to improve risk prediction for cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Materials and Methods: In this retrospective single-center study, we analyzed 407 patients with cytological reports of ASC-US, ASC-H, or AGC. All patients underwent HPV DNA testing with genotyping for 21 types, with viral load quantification for HPV16/18, and subsequent histological verification. Statistical analyses included non-parametric tests, correlation analysis, and multivariate logistic regression to identify independent predictors of CIN2+. Results: The prevalence of CIN2+ differed significantly among the cytological categories: 23.2% in ASC-US, 47.3% in ASC-H, and 19.5% in AGC. ASC-H and a high HPV16 viral load were identified as independent predictors of CIN2+ in the multivariate analysis. An ASC-H result increased the probability of CIN2+ by 2.5 times (aOR = 2.51; 95% CI: 1.28–4.94). For each 1 log10 increase in HPV16 viral load, the risk of CIN2+ increased by 30% (aOR = 1.30; 95% CI: 1.16–1.46). Stratification of ASC-US cases by HPV16 status revealed a dramatically higher positive predictive value (PPV) for CIN2+ in HPV16-positive patients (66%) compared to HPV16-negative patients (12.6%). The AGC category showed the strongest association with glandular pathology, including adenocarcinoma in situ. Conclusions: The combination of cytological findings and HPV16 viral load provides a powerful model for risk stratification. An ASC-H result is a strong independent risk marker, while the clinical significance of ASC-US is fundamentally determined by HPV16 status. These findings advocate for a risk-based management algorithm that integrates liquid-based cytology with extended HPV genotyping and viral load assessments to optimize patient triage and follow-up.

Background/Objectives: Fumarate hydratase-deficient leiomyomas (dFH-LMs) are a rare subtype of uterine smooth muscle tumors (USMTs) with implications for hereditary leiomatosis and renal cell carcinoma (HLRCC). Although several morphologic clues have been proposed, their diagnostic reproducibility is poorly defined. We aimed to determine the diagnostic significance of histopathologic features associated with fumarase deficiency and the reproducibility of key morphologic criteria for defining dFH-LMs. Methods: A retrospective analysis was performed on 45 USMTs that were initially classified as atypical leiomyomas (ALMs). The cohort comprised patients aged 21 to 75 years who had surgery at one tertiary medical care center from 2016 to 2025. Hematoxylin–eosin (H&E) slides were independently examined by three pathologists for features associated with FH deficiency, including eosinophilic globules, staghorn-like vessels, diffuse nuclear atypia, “bizarre” nuclei, and prominent nucleoli with halos. Molecular status was determined by immunohistochemistry (IHC) for fumarate hydratase (FH) and S-(2-succino)-cysteine (2SC). Interobserver agreement was quantified using Fleiss’s κ and Cohen’s κ. Results: Loss of FH expression was detected in 26/45 tumors (57.7%). Eosinophilic globules occurred in 88.5% of dFH-LMs, but only in 15.8% of ALMs (p < 0.001). By majority consensus (≥2 of 3 reviewers), the eosinophilic globules predicted FH deficiency with a sensitivity of 88.0% and a specificity of 85.0%; interobserver reproducibility was substantial (κ = 0.63). Staghorn-like vessels occurred in 73.1% of dFH-LMs vs. 26.3% of ALMs (p = 0.02) and diffuse nuclear atypia (84.6%) was also more frequent in dFH-LMs (p = 0.01). Patients with dFH-LMs were significantly younger than those with ALMs (Median, 34 vs. 41 years). Conclusions: Eosinophilic globules, staghorn-like vessels and diffuse nuclear atypia have been shown to have high diagnostic value and could be considered morphologic indicators of dFH-LMs. The substantial interobserver reproducibility of eosinophilic globules makes this feature particularly promising for routine clinical practice.

Background/Objectives: Low-grade serous ovarian carcinoma (LGSOC) is known as an uncommon subtype of cancer with poor response to standard chemotherapy, so novel targets are required. The current study aims to highlight the Human Epidermal Growth Factor Receptor-2 (HER2/neu) immunohistochemical (IHC) expression in LGSOCs. Methods: The study was conducted using 33 cases of LGSOCs from the calendar years 2017–2024. IHC staining was performed using antibody anti-HER2/neu (clone 4B5). HER2/neu scoring was performed based on the American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) criteria for breast carcinoma. Results: The mean age of the 33 patients was 46.5 years. International Federation of Gynecology and Obstetrics (FIGO) stage data for patients revealed a predominance of advanced disease: 82.7% (24/29) were in advanced stages. Early stages comprised 17.3% (5/29) of cases. The study did not find HER2/neu overexpression in all cases. In 3.0% of samples (1/33), HER2/neu IHC staining was scored as 1+, and in 6.1% (2/33) of all LGSOCs, ultralow phenotype was observed. Of 23 cases in the HER2-negative group, 6 patients were alive with progressive disease, 1 patient died in 5 months, and 16 were alive with no evidence of disease. Of two patients with the HER2-ultralow phenotype, one was alive with no evidence of disease at 16 months follow-up. Conclusions: The results support the idea that HER2/neu overexpression is exceptionally rare in LGSOC; nevertheless, future trials are essential to fully characterize the spectrum of HER2/neu alterations in LGSOC and to determine definitively whether the rare cases with mutations or ultralow expression could represent a small subgroup that might benefit from specific targeted agents.